When weeds pop up in the lawn, it is easy to drive straight to the garden center and buy herbicide to solve the problem. Although herbicides are effective, weeds will return with a vengeance unless the lawn is properly maintained. A lawn maintenance schedule ensures the turf grows dense and green, which reduces the likely hood of weeds popping up in the lawn. Herbicides are best used as a last resort when all cultural practices are exhausted.
Mow your lawn frequently, says the University of Wisconsin, setting your mower at 2 1/2 to 3 inches in height. Cutting heights may vary according to grass variety. Remove only 1/3 of the grass blade per mow to reduce stress on the plant. Cutting correctly invigorates growth of the roots and reduces thatch.
Water your lawn thoroughly in the morning, watering infrequently but deeply. Low-maintenance lawns require around 1 inch of water per week. Frequent shallow watering weakens the lawn by stunting root growth, says the University of Wisconsin.
Apply 1 lb. of nitrogen per 1,000 feet of turf in mid-October and in June to protect the grass from the winter months. Fertilizing replaces nutrients and promotes lush, healthy growth.
Dig up weeds when they appear in isolated spots, getting as much of the root out of the ground as possible to prevent regrowth. Removing weeds early in the season prevents seeds from spreading.
Apply a pre-emergent herbicide in the early spring, before mid-April, to prevent the germination of weed seeds, says the University of Missouri. Follow the label instructions for application rate and method. Apply granular herbicide using a drop spreader, running half of the application in one direction of the lawn, then the other half crisscrossing the first pass.
Spray a post-emergent herbicide on weeds if cultural methods have not reduced their appearance. Wear safety goggles, work gloves and long clothes to prevent poisoning. Apply according to the label instructions.